[单选题]
A solenoid with 500 turns is 0.10 m long anp(x1g d 9ovqi(d carries a cu*+b jkxp.cmt s8yj 91kzy hng,bka0 :(rrent of 4.0 A. What strength of ,+ 9:yk1j kj bk(mzhb* 8x.s tcna0pgymagnetic field will it have at its center?
A. $3.1 \; mT$
B. $6.2 \; mT$
C. $13 \; mT$
D. $25 \; mT$